what are you talking about specifically? your question is very ambiguous.

LinuxMCE, like its close cousin, Pluto, can stream video to any of its connected machines (called Media Directors) throughout the house, either individually, or in groups simultaneously. It does this by sending the video streams from the machine that has the media (typically the CORE), to the other machines requesting the stream. Since this is over TCP/IP... I guess you could call it IPTV... or are you referring to some proprietary protocol?

I think he is asking about where TV is delivered to your house over IP, as far as I know it you have a special box that does the decoding etc for viewing on the TV.

You don't necessarily need custom hardware and you could certainly interface to a IPTV service from a technical perspective using lmce using software and suitable video hardware. I think the issue is that as it stands lmce does not have any UI to allow for services delivered this way... but a UI could certainly be added to support such services.

I think it'd be good if LMCE will support IPTV. But IMHO it's too difficult to add full features set like schedule, record, pausing. It's easy to control STB similar way as it's done for Dreambox. But no more.